Diagnostic Findings [Last Modified: ]
Microsporidiosis
[Brachiola spp.] [Encephalitozoon cuniculi] [Encephalitozoon hellem]
 [Encephalitozoon intestinalis (syn. Septata intestinalis)]
 [Enterocytozoon bieneusi] [Nosema spp.] [Pleistophora sp.]
 [Trachipleistophora spp.] [Vittaforma corneae (syn. Nosema corneum)]
Causal Agent Life Cycle Geographic Distribution Clinical Features Laboratory Diagnosis Treatment

Light microscopy
Different staining techniques can be used to demonstrate microsporidian spores in clinical samples.

The spores appear as oval to round shaped structures, measuring 1 to 4 µm (depending on the species).  Some stains (Gram, Chromotrope 2R [A], and Quick-Hot Gram Chromotrope [B]) highlight a belt-like stripe in the equatorial diameter of the spores.

Spores stained with Chromotrope 2R
A

A: Stool smear stained with Chromotrope 2R containing Enterocytozoon bieneusi spores.  Black arrows indicate E. bieneusi spores with their belt-like stripe accentuated.  Red arrow indicates an unidentified yeast.  The yellow arrow indicates a vacuolated spore.

Spores stained with Quick-Hot Gram Chromotrope
B

B: Stool smear stained with Quick-Hot Gram Chromotrope stain containing Enterocytozoon bieneusi spores.  Black arrows indicate E. bieneusi spores with their belt-like stripe accentuated.  The red arrow indicates an unidentified yeast.  The yellow arrow indicates a vacuolated spore.
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